Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of base stations (e.g., eNodeBs) that can support communication for a number of user equipments (UEs). A UE may communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.
In multiple connectivity, the UE can be configured to communicate with multiple cells or cell groups configured by multiple base stations using multiple links. In this configuration, the multiple cells or cell groups may not be synchronized in time, which may result in failure of certain procedures that may benefit from timing alignment among the cells or cell groups. Such procedures may include defining measurement gaps during which a UE can tune away from the multiple cells or cell groups to measure cells of other frequencies or radio access technologies, discontinuous receive (DRX) mode operations where the UE receiver is active only during certain durations to lower power consumption, etc. If the multiple cell or cell groups are not time aligned for such procedures, however, the UE transceiver may miss signals from one cell or cell group during a measurement gap defined by another cell or cell group or in an idle period for a DRX mode defined by another cell or cell group.